Hi Simon 
These are some interesting questions, my only concern is that if Monzo takes the time to answer all of them, they won’t have time to build a bank 
Here’s what I know (this should be quick) -
1 & 2. Overdrafts will be Monzo’s first product, they’ve explained their vision for them here & discussed how they should work in practise here. If you search the community for @paul / @venkat / @luba you find some more info from the team that’s working on them too 
.3. One way that Monzo will treat their customers more fairly is that unlike the legacy banks, they won’t rely on punitive charges to fund their current accounts. As you may know, these charges mean affect the less well off (the people who need to use overdrafts & will potentially end up going into their unplanned overdraft) the most. While those who have a positive account balance pay no fees at all… 
Rather than offering premium service - I don’t know if that’s something Monzo are considering but it seems against their whole approach - Monzo wants to do the opposite. Jonas (one of Monzo’s Co-Founders) has said that he wants Monzo to be able to provide their current accounts to the unbanked, by the end of the year 
.4. Monzo is a commercial bank but as you’ve probably noticed, they have invested a significant amount of time & effort setting up crowdfunding campaigns to enable customers to invest, as part of each major round of fundraising. Having said that, it looks like there simply aren’t enough users to entirely fund Monzo, with it’s current business model so they’re having to raise capital from private investors too 
.5. My concern with using Bitcoin to avoid inflation would be the massive volatility of the currency. That has a far greater impact on the value of money held in Bitcoin, than inflation does on pounds sterling 
.6. Monzo has a banking license so below the central bank. Regulation makes this a necessary constraint & also helps protect consumers 
.7. Monzo already uses gamification - Targets are one example & I love it 
I’ll leave the biggest questions to Monzo